May 1, 2011
Joshua Buck
Headquarters, Washington
202-358-1100
jbuck@nasa.gov
Candrea Thomas
Kennedy Space Center, Fla.
321-867-2468
candrea.k.thomas@nasa.gov
RELEASE: 11-131
SHUTTLE ENDEAVOUR LAUNCH NO EARLIER THAN MAY 8
CAPE CANAVERAL -- NASA managers have determined space shuttle
Endeavour will not launch before Sunday, May 8, but will not
officially set a new launch date until early this week.
After Friday’s launch scrub, Kennedy Space Center technicians searched
for the cause of a failure in a heater circuit associated with
Endeavour’s hydraulic power system. The failure was found to be in a
power circuit in a switchbox in the shuttle’s aft compartment.
Managers and engineers are developing a schedule to remove and replace
the switchbox and retest the new unit. That work will delay
Endeavour’s launch until at least May 8.
The shuttle has three Auxiliary Power Units (APUs) that provide
hydraulic power to steer the vehicle during ascent and entry. The
hydrazine fuel lines on each APU have two heater circuits that
prevent the fuel from freezing while the shuttle is in space. NASA
launch commit criteria and flight rules require all three APUs and
heater circuits to be operational for liftoff.
Endeavour’s six astronauts have returned to NASA’s Johnson Space
Center in Houston for several days of additional training. For the
latest information about the shuttle mission and its crew, visit:
http://www.nasa.gov/shuttle
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